"...that girder piece (you offered) cleaned up really nice - but when I held it up to the Revell stern area - it's way too big...Your piece is larger in height and width, yet it appears VERY accurate proportionately...I am sure you have discussed this online before, but are we dealing with a significant difference in scale between the Renwal and the Revell kits, or is it that Renwal got the whole hull width more correct than did Revell, who kind of ignored this "minor" detail?"

Actually, Kevin, we haven't really discussed this yet - so let's do so right here - and the short answer to your questions is: yes - to both - though it isn't Renwal, but the Lindberg kit, on which I built the fantail correction. Which, BTW - and for anyone(s) needing to get up to speed - looks currently like this:

The Lindberg Essex, like my Boxer build on it, actually depicts a straight-decked Essex, and not an SCB-125 like the Revell kit - however the major fantail features, as visible here, remained essentially unchanged between the two. Of these, the piece Kevin mentioned above duplicates the girder detail at top (enclosing the gallery, on the real thing) immediately under the flight deck overhang (not shown), along with the two pillars below, supporting it. Note, midway up the pillars is located an intermediate deck, creating a "three-level" effect - however the top "level" is not a deck, but an overhang - what would be called a soffit, in building construction (and maybe also aboard ship?).

Three distinct "500-ish" Essex kits depict - or fail to depict (see below) - these features right out of the box, as follows:

Click on Image to Enlarge

At top, the Revell Essex mold - though plagued as ever with its molded-on railings - does depict all the main features, but gets the top (overhang) wrong - depicting it as yet another deck (with yet more railing molded in), and narrower than the one below. That intermediate deck does correctly extend out to the edge of the main deck, below it - but the top overhang should extend out to the edge of the flight deck.

At middle, the Renwal Essex mold depicts only the intermediate deck, ommitting entirely both the girdered overhang and support pillars - in fact, seeming to invite the builder to provide exactly this detailing - even presenting a ledge up under the top, on which to rest the soffit assembly! I have seen enough instances like this with Renwal - and especially Lindberg - to have concluded that this was indeed deliberate: to completely leave off details which the modeler could build better than they, in those early days 50 years ago, could mold in the plastic.

Even so, the Lindberg Essex, at bottom, really pushes it too far - ommitting all fantail structures - which was enough "invitation" for me to build all of it, as shown above.

However, in addition to Revell's errors mentioned above, there are indeed scale differences - and more - which separate these kit fantails, one from another:

Click on Image to Enlarge

The Lindberg hull under my correction (left top and bottom), is nominally 1/525 scale, and is in fact the only one of the three having correct overall proportions. The Revell hull (top right), though narrower due to its smaller (nominal) scale of 1/540 is additionally narrower because its beam is incorrectly small, as we actually measured earlier, appropriate to a scale of 1/622!

Add to the above, the inaccurately-narrow top overhang "soffit" part, and its no wonder my part looks a lot larger. Bottom line, for the Revell Essex: chop out as much center-section of the upgrade as required to close up the support pillars to the right separation - re-attach at a joint made into a central girder - and trim the outboard edges flush with those of the flight deck.

And you're (ironically) right that indeed the match is much better for the Renwal Essex (bottom right), nominally 1/500 scale and with (at least roughly) correct beam for the length (though I haven't measured it out). The Renwal Essex hull's problem is that it's too squat (too low freeboard) as readily seen in the image - but this fault has no impact on the fantail correction, being as it is, entirely above the main deck level.

And that's the lowdown on fantail details - and lack thereof - on the three, "500-ish" Essex class kits. Sorry for the delay in the above reply, Kevin - I hope it was worth it, and gives you (and everybody) some ideas.